Car will not rev, bad misfire, low vac at idle

[Ippkiss]

Ok, I'm a little stumped on project 1300$ whore

Car ran decent when I bought it. Idle surge, but it ran. Car had massive coolant leak that turned into blown head gasket. Car ran well enough to drive it 60 miles home

Car is 1991 GSX a/t. Car supposedly has 450's & M/T ecu.

while the head was off I did:

Replaced head gasket
replaced intake manifold gasket (thermal insulation gasket)
replaced tb elbow gasket
replaced or deleted vac lines
replaced turbo (e3 16g)
ported turbo, 02 housing & exhaust maini
all new gaskets on exhaust side
upgraded grounds from cylinder block & head, frame rail to battery
1g M/T cams
new timing belt, water pump, balance shaft belts, tensioner, pulleys, & crank damper
arp head studs
fixed coolant temp sensor connection (car has a hacked to #### wiring harness)
head was broken down to bare casting and cleaned because of metal shavings found in it.


Car starts, idles, will free rev but you can tell it has a miss to it. Tried to adjust base timing down, but timing seemed very erratic even with the proper pin grounded. Could have been a bad ground on this.

When put in gear car revs to aprox 1400-1500 rpms, and stops.

Idle vac is very low, at around 13-14", Seems like timing belt could be off.

Compression is a steady 140 psi across the board maybe up down 2-3 psi. I'm at 4800 ft ASL so these seem like fine numbers to me. Would having the timing belt off cause this while still allowing good comp #'s?

No o2 sensor on the car right now, but it seemed to be doing ok with out one before. The harness has been hacked off, and I haven't quite figured out which wires go where yet.

Supposedly car had brand new NGK wires & plugs just before I got it, I'm about to replace plugs just to see if it does anything. Old plugs came out looking rich, lots of black soot. Put in brand new NGK's & did not change anything.

Car has been leak tested and most of the vac leaks are gone, the few small ones (very small leak on biss screw, tb shaft also needs new o rings) don't seem to be enough to piss of the car this much.

Car did have CEL for no coolant temp sensor connected, but I fixed that part of the wiring. Logger shows air flow from the MAS, so I believe it is plugged in & working.

I am getting some decent lifter tick, maybe a lifter has gone bad.

 

[TwoLiterLaser]

Man you got yourself a bag of fun......

You say you tore down the head: Did you put the valves back in the exact position they came out of? How where the valves?(Where they pitted? Where there scratches on the stems?) Are you sure they where straight? Did you have the ehad at the machine shop for inspection/milling?

You should have a CEL for the O2 sensor being gone. I would attribute most of your problems to you not having any O2 sensor.

The AT pressure regulator runs at a different fuel pressure than the MT, it is a small difference, but combined with no O2 sensor, the 450's and a MT ECU and I can safely say that you are just dumping tons of fuel into that engine.

I would start small then work your way up:

1. O2 sensor
2. Plugs
3. Wires
4. Boost/Vacuum leak test
5. Timing
6. Remove head and inspect it all again, put it back together.....

A bad lifter would cause some ticking, but not anywhere near everything you have described. Depending on where your timing is off, you could still have good comp numbers but not run correctly. Good luck and just take your time.

 

[Ippkiss]

Man you got yourself a bag of fun......

You say you tore down the head: Did you put the valves back in the exact position they came out of? How where the valves?(Where they pitted? Where there scratches on the stems?) Are you sure they where straight? Did you have the ehad at the machine shop for inspection/milling?

You should have a CEL for the O2 sensor being gone. I would attribute most of your problems to you not having any O2 sensor.

The AT pressure regulator runs at a different fuel pressure than the MT, it is a small difference, but combined with no O2 sensor, the 450's and a MT ECU and I can safely say that you are just dumping tons of fuel into that engine.

I would start small then work your way up:

1. O2 sensor
2. Plugs
3. Wires
4. Boost/Vacuum leak test
5. Timing
6. Remove head and inspect it all again, put it back together.....

A bad lifter would cause some ticking, but not anywhere near everything you have described. Depending on where your timing is off, you could still have good comp numbers but not run correctly. Good luck and just take your time.

I said bare casting, but in reality the valves & springs stayed in. I pulled all of the allen plugs, lifters, cams, ect and took the bottle brushes to it. Then througly degreased it, & pressure washed the shit out of it.

The head was not checked by a machine shop, but I did put a straight edge up to it to check for warpage. The valves/combustion chamber both looked very good, no pitting, not too much carbon build up, no scoring ect. I was pretty sure that if the head went to a machine shop, this would snowball into a 2.4 stroker build which I do not have the money for at the moment. we all know what happens with an "while I'm in there i might as well..." type of situation.

The metal shavings came from a bad helicoil job on the turbo oil feed line. pretty much everything on this car has been hacked up.

There was a decent vac leak from my tb to intake mainfold, but I have cured that down to almost nothing.

Plugs are brand new, wires will be swtiched out shortly also.

As soon as I can, The o2 sensor will be hooked up. I worked out a deal with a friend to pick up a 90 GST thats been wrecked for 700$. That will give me a whole spare parts car, & virgin wiring harness to use.

with the m/t ECU (I'll be checking parts numbers to make sure), 450's & cams, should I just adjust the fuel pressure to what is called for a stock M/T then?

 

[link16]

Is the car a M/T still or no, it would make no sense to put it at stock M/T fuel pressure level if it is a A/T...Set it to A/T levels and see if that helps, also check your timing.

 

[Ippkiss]

Is the car a M/T still or no, it would make no sense to put it at stock M/T fuel pressure level if it is a A/T...Set it to A/T levels and see if that helps, also check your timing.

If it has a manual trans ecu, manual trans 450 cc injectors, and m/t cams, the ecu is going to be set to run at the m/t fuel pressure, not a/t fuel pressure I would think. I'm sure about all this 1g auto b/s, the last dsm a/t I had was a 2g and didn't have all this different bull shit.